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In May, cicada nymphs will appear by the handful in areas
treated to Brood II.

News came last week that somewhere in Stokes County, NC,
Brood II cicadas were seen. In parts of Stokes County, growing degree days from
January 1, 2013 have exceeded 360 and this seems to be warm enough to convince
these teenagers that the time has come to greet the sun. Like a huge tsunami,
this exodus will continue to roll up the eastern seaboard from North Carolina to
the Hudson Valley in New York and eastward to central Connecticut as the warmth
of spring extends its northern reach. In the path of this biological deluge are
major metropolitan areas and their suburbs including Hartford, New Haven, New
York City, Philadelphia, and southern suburbs of Washington, DC. One report has
it that periodical cicadas may even be seen in Central Park, NY.

Where cicadas are present, hundreds of exit holes and mud
turrets can be found under leaf litter beneath trees.

As a child growing up in Morris County, New Jersey, I fondly
recall the appearance of Brood II in 1962 and the adolescent hysteria it
created on the playground where my classmates feigned bravado or openly shrank
in terror from the noisy horde. Nymphs have been feeding underground on xylem
fluid from plant roots for the past seventeen years. This dismal existence is
about to come to a screeching end. Over the past several weeks, nymphs constructed
escape tunnels to the surface of the earth. Soil temperatures in the middle sixties
are the cue that the world above ground is warm enough to support flight,
escape from predators, and reproduction. Many nymphs emerge at night and make a
mad dash for vertical structures such as trees and shrubs whereupon to make the
final molt to adulthood; however, lampposts, street signs, and slowly moving
people seem to work just as well. After climbing up and away from the soil,
they attach to a firm object to begin the process of molting. Their outer skin,
or exoskeleton, splits along a predetermined line on their back and the
beautiful adult cicada wiggles free from the shell. The freshly molted adult is
almost pure white except for bright red eyes and patches of black behind the
head. Before the exoskeleton hardens, the cicada must expand its wings or it
will be unable to fly and seek a mate. After wings and legs have hardened,
cicadas scurry or fly to the treetops where courting, mating, and egg laying
occur. The visit of the periodical cicadas above ground will be short, and by
the end of June their carcasses will return to the earth and fertilize the
roots of the trees from which they spawned. What a curious and marvelous turn
in the revolving circle of life.

My friends in Washington DC area have asked if they will
enjoy a visit by cicadas this year. One map listed below holds some hope that
Brood II may appear near the district. However, cicada guru John Zyla has
produced a wonderful cicada map for our region that puts the nearest emergences
of Brood II in Calvert, St. Mary’s, Fairfax, Fauquier, and Prince William
Counties. This map can be found at the link below. Over the past several weeks,
I have investigated several potential sightings of cicadas in Anne Arundel and
Calvert Counties in Maryland and come up empty. Several reports of “numerous
holes” in the ground were actually galleries constructed by ground nesting
solitary bees.

This
little cicada has a couple weeks to go before she makes her grand appearance.

Earlier this spring, I and one of my colleagues were fooled
by the call of an amphibian that sounded surprisingly reminiscent of a cicada
song. However, at one site in St. Mary’s County, I recently discovered a soggy
woodlot loaded with Brood II nymphs. As of last week, these little rascals were
still deep in their burrows and had yet to develop the dark patch of color just
behind their head that signals their imminent emergence from the earth. My best
guess is that the exodus from below is still a couple of weeks down the road.
This schedule fits well with the last brood of cicadas to emerge in St. Mary’s
County, Brood XIX, which appeared in the latter half of May in 2011 (see St. Mary’s Survivors, June 6, 2011). I fear that DC,
Montgomery, and Prince George’s are out of luck this time for enjoying cicadas
in the back yard, but who knows, maybe the cicadas will deliver us a surprise. Nonetheless,
as these marvelous creatures make their presence known, it will be well worth a
trip to a nearby location to witness this remarkable event.

References

This episode was inspired by Deak and Sheri, who lead the
discovery of the Far Hills cicadas. The wonderful article by K. S. Williams and
C. Simon “The ecology, behavior, and evolution of periodical cicadas” was used
as a resource for this episode.

To see John Zyla’s cicada map and other cicada maps, please
click on the following links: